An ultraviolet (UV) blocking agent used in a cosmetic composition can be largely classified into an organic UV blocking agent and an inorganic UV blocking agent according to its properties. Of them, the organic UV blocking agent blocks UV rays by absorbing the energy of UV rays that reach on the skin, and it has advantages over the inorganic UV blocking agent—it is less susceptible to whitening, it can effectively block UV rays when applied to the skin because it is applied to the skin in molecular state, and it can be developed in light formulation, such as in the form of milk type, gel, and lotion as well as in the form of cream or foundation.
Hydrophobic polymer foams such as NBR and SBR are being widely used as a material for cosmetic composition impregnation because of having good wear resistance or oil resistance, but their disadvantage is low workability.
To solve the problem of the hydrophobic polymer foams, natural rubber (NR) is used for a polymer substrate for making a foam. Due to its good compatibility with hydrophobic polymers such as polyethylene, polypropylene, polystyrene, and polyester, formed by polymerization of hydrophobic monomers such as ethylene, propylene, styrene, and ester, NR is widely used as a material for blending with other hydrophobic polymer when making a foam. Particularly, when it is used for cosmetic composition impregnation, NR has advantages—it feels good and has good mechanical properties such as wear resistance. However, the present inventors found the fact that an adsorption problem of an oil soluble organic UV blocking agent occurs in an impregnation material used together with NR. To solve the problem, an attempt is made to solve the adsorption problem of an oil soluble organic UV blocking agent that occurs when both NR and NBR are used for a polymer substrate.